I always consider that the early seasons were them throwing a lot of shit at the wall to see what sticks and feels right, and then they actually followed through on that. Like how the quantum mirror episode carried a lot of water for later plot points. They just didn't take themselves seriously from the get go, and were able to figure out something that works, so the cringe stuff doesn't even feel that bad in the long run, we just move on, it's not coming back anyway.

Plus there's a couple of big episodes that were in surprisingly early seasons, like the "crystal boy tries to heal O'Neill", that showed what kind of stories they wanted to make, that it was worth keeping up with.